The Virtual Microscope

Part 1: The parts of the microscope

Diaphragm

Light source (lamp)

Fine-adjustment knob

Coarse-adjustment knob

Body tube

Objective lens

Revolving nosepiece

Condenser lens

Eyepiece

Arm

Base

Stage and clips

Select a part of a microscope by choosing its name or by direct selection on the model to learn more about it.

Procedure (red blood cell)

1. Turn the light on under your microscope.
2. Load the the human red blood cell slide by selecting a slide button. This is an example of an animal cell.
3. Use the coarse-adjustment knob to focus the slide as best you can.
4. Then use the fine-adjustment knob to bring the image into sharp focus. You are actually viewing many red blood cells.
5. Select the 100 x magnification (100×).
6. Use the coarse-adjustment knob to focus the slide as best you can.
7. Then use the fine-adjustment knob to bring the image into sharp focus. You are actually viewing many red blood cells.
8. Select the 1000 x magnification (1000×).
9. Use the coarse-adjustment knob to focus the slide as best you can.
10. Use the fine-adjustment knob to refocus the slide under the higher magnification.
11. Turn on the scale and determine the field diameter at 1000×. For this microscope, the field diameter at 40× is 2 mm. To simplify your calculation, assume that the ocular scale occupies the whole field diameter so that the 10 ocular scale divisions equal 2 mm under 40×.
12. On a piece of paper, make a biological drawing of a red blood cell as seen through the microscope under 1000× magnification. Because red blood cells are so small, you will not be able to see many internal cell details at this magnification, so just draw what you can see. Estimate the size of the cell.

Procedure (onion skin cell)

1. Select the three small images below to view cells at low (40×), medium (100×) and high (1000×) magnification.
2. On a piece of paper, draw one of the onion skin cell samples under 1000× magnification. You will only be able to see certain large structures at this magnification (cell wall, membrane, nucleus, vacuole, and so on) so draw what you see.
3. Estimate the approximate size of the cell by how large it seems in relation to the field diameter.

   40x        100x        1000x